Texaphyrins: a new approach to drug development

The texaphyrins are prototypical metal-coordinating expanded porphyrins. Th ey represent a burgeoning class of pharmacological agents that show promise for an array of medical applications. Currently, two different water-solub le lanthanide texaphyrins, namely motexafin gadolinium (Gd-Tex, 1) and mote xafin lutetium (Lu-Tex, 2), are involved in multi-center clinical trials fo r a variety of indications. The first of these agents, XCYTRIN(R) (motexafi n gadolinium) Injection, is being evaluated as a potential X-ray radiation enhancer in a randomized Phase III clinical trial in patients with brain me tastases. The second, in various formulations, is being evaluated as a phot osensitizer for use in: (i) the photodynamic treatment of recurrent breast cancer (LUTRIN(R) Injection; now in Phase IIb clinical trials); (ii) photoa ngioplastic reduction of atherosclerosis involving peripheral and coronary arteries (ANTRIN(R) Injection; now in Phase II and Phase I clinical trials, respectively); and (iii) light-based age-related macular degeneration (OPT RIN(R) Injection; currently under Phase II clinical evaluation), a vision-t hreatening disease of the retina. In this article, these developments, alon g with fundamental aspects of the underlying chemistry are reviewed. Copyri ght (C) 2001 John Wiley & Sons, Ltd.